How to Set Up for Photo-Matching in Google SketchUp 8

Photo-matching in Google SketchUp allows you to build a model based on a photograph or match your model view to a photograph. If you have a good photograph (or multiple photographs) of the thing you want to model, SketchUp’s photo-matching feature can help you set up things up so that building your model is much easier.

Or perhaps you have a model of a building and a photograph of the spot where the building will be constructed. You can use photo-matching to position your camera in SketchUp to be exactly where the real-life camera was when the photograph was taken. Then, you can create a composite image that shows what your building will look like in context.

Photo-matching works only on photographs of objects with at least one pair of surfaces that are at right angles to each other. Luckily, this includes millions of things you may want to build, but still, if the thing you want to photo-match is entirely round, or wavy, or even triangular, this method won’t work.

Whether you’re building a new model or lining up an existing model with a photograph, start by getting your modeling window ready. How you do this depends on which one you’re trying to do:

Line up a model you've built already with a photograph: This case requires you to re-orient your view and then reposition your drawing axes before you’re ready to begin photo-matching.

Use a photograph to build a model: Open a fresh, new SketchUp file, and you’re good to go.

After your modeling window is set up, follow these steps to create a new matched photo in your SketchUp file:

Choose Camera, Match New Photo.

Select the image on your computer that you want to use and click the Open button.

The dialog box closes, and you see the image you chose in your modeling window. You also see a jumble of colorful techno-spaghetti all over the place. Don’t worry; it’s all part of the photo-matching interface.

Begin positioning the perspective bars, starting with the two green ones, by lining them up with any two parallel edges.

The tops and bottoms of windows are good candidates, as are rooflines, tabletops, and ceiling tiles. This is easier than it looks. Move each perspective bar one at a time, dragging each end into position separately.

Line up the two red perspective bars with a different set of parallel edges — just be sure that these parallel edges are perpendicular (at right angles) to the first pair.

Drag the axis origin (the little square where the axes come together) to a place where your building touches the ground.

This is how you tell SketchUp where the ground plane is. Try to make sure your axis origin is right at the intersection of two perpendicular edges.

If you’re photo-matching an existing model, dragging the axis origin moves your model, too. Line up your model with the photograph so that the spot where you placed the axis origin is right on top of the corresponding spot in your photo.

Roughly set the scale of your photograph by clicking and dragging anywhere on the blue scale/vertical axis line to zoom in or out until your photograph looks to be at about the right scale.

Do this by first setting your grid spacing in the Match Photo dialog box and then using the grid lines in your modeling window to eyeball the size of your photo until it looks about right.

If you’re trying to match an existing model to your photo, just zoom in or out until your model looks like it’s the right size. You don’t have to be very exact at this stage of the game. You can always scale your model later.